What is Mallet Finger Injuries?
Mallet finger is a condition often linked to fractures caused by tearing away of the extensor tendons, which are responsible for straightening our fingers. This condition can also result from tears in the extensor tendon located at the farthest end of the finger. Either situation leads to difficulties in extending or straightening the fingertip joint. This condition is named ‘mallet finger’ because the finger deformity it causes looks like a mallet or hammer. This happens due to a problem with the extension mechanism of one of the finger bones at the distal interphalangeal joint, commonly triggered by forceful bending towards the palm at this joint. This injury leads to an inability to straighten the farthest end of the finger.
In some cases, a mallet fracture can occur where the extensor tendon not only gets ruptured but also causes the end bone of the finger to tear away. There are three categories of mallet fractures depending on the patient’s age and how much of the surface of the end finger bone is affected. The choice of treatment for this condition is still somewhat disputed but typically depends on how much of the finger bone’s surface is involved in the fracture.
What Causes Mallet Finger Injuries?
The end part of an extension tendon in your finger is torn. This kind of injury typically happens when the last bone of your finger is forcefully bent while you are actively trying to straighten your finger. Starting from your forearm, this extension tendon travels over the joint where the hand and fingers meet, attaches indirectly to the nearest bone of your finger, and finally attaches to the furthest bone of the finger. These tendons are the reason you can straighten your fingers.
A ‘mallet finger injury’ is when the extension tendon is damaged or torn. Alternatively, a ‘mallet fracture’ refers to when the torn tendon pulls a piece of the bone where it attaches, causing a tiny breakage in the finger bone.
Risk Factors and Frequency for Mallet Finger Injuries
Mallet finger injuries are common in workplaces or during sports activities, especially those involving ball games. This happens when a ball strikes the tip of an outstretched finger, forcing the joint of that finger into an abnormally bent position. This then damages the tendon that makes extension of the finger possible. Mostly, the injury tends to happen to the long, ring or pinky finger of the hand you use most. It is more frequently seen in young to middle-aged men, but can also occur in older women.
- Mallet finger injuries often result from either workplace incidents or sports activities.
- Ball sports can increase the risk of these injuries due to the chance of a ball hitting the extended fingertip.
- This event forces the last joint of the finger into an unnatural bend, disrupting the tendon that extends the finger.
- Mostly, the long, ring, or little finger of the dominant hand are affected.
- This injury is typically seen in young to middle-aged men and occasionally in older women.
Signs and Symptoms of Mallet Finger Injuries
Mallet finger injuries are typically diagnosed based on the symptoms a patient expresses. These can include experiencing a forceful bending of the finger, pain, a bent or misshapen appearance, or trouble using the affected finger.
During a physical examination, the healthcare provider will take a close look at the soft tissues of the finger. They will examine the main joint in the middle of your finger (the metacarpophalangeal joint) and the joint closest to your hand (the proximal interphalangeal joint) to check their range of motion. They will also evaluate the joint at the end of your finger (the distal interphalangeal joint). If you have a mallet finger injury, the fingertip will typically be at about a 45-degree angle, and you might have trouble straightening it. Depending on when you got hurt, there might also be swelling or tenderness around this joint.
Testing for Mallet Finger Injuries
A mallet finger diagnosis is often made based on a doctor’s assessment. Yet, to understand whether you have a mallet finger injury or mallet fracture, the doctor may need to take three different X-rays of the affected finger. Using these X-rays, the doctor can identify whether there’s a bone chipped away at the end of your finger, which signifies a mallet fracture, or if the X-ray appears normal, indicating a mallet finger caused by a ligament injury.
The most helpful X-ray is a side-facing one of the affected finger. This image can help the doctor find out the size of the bone chip (if there is one), how much the bone chip has moved, and whether the end of your finger bone has shifted out of place.
Treatment Options for Mallet Finger Injuries
The best way to treat a mallet fracture is still disputed within the medical community. Generally, a mallet fracture involving less portions of the joint area without any associated subluxation (partial dislocation) can be handled without surgery. A supportive tool called a splint is typically used.
While in the past both the proximal and distal joints were immobilized, recent research has shown that immobilizing the proximal joint may not be necessary. As a result, it’s generally recommended to only immobilize the distal joint. Your finger will usually be lightly stretched (0 to 10 degrees extension) with a splint on this joint for about 6 to 8 weeks, followed by partial time use of the splint for another 4 to 6 weeks.
There are many kinds of splints that could be used for a mallet finger injury, including stack splints, perforated thermoplastic splints, and aluminum-foam splints. No matter what kind of splint is used, it’s important to completely immobilize the joint for around 6 to 8 weeks, followed by using the splint only at night for an additional two weeks. Once the immobilization period is up, you can begin exercises that help increase the range of motion in your finger. You’ll need to restart your treatment if the joint bends accidentally.
If the mallet fracture is more severe, covering more of the joint’s surface or resulting in subluxation, surgery is typically the accepted treatment. A number of surgical methods are available for treating mallet fractures. Just like with splinting, a common feature of most surgical treatments is immobilizing the distal joint in a fully extended position, usually with a type of surgical pin called a Kirschner wire. This pin is often introduced in a closed reduction technique, a procedure that helps align the broken bone followed by placing the pin, to avoid complications such as pain, infection, skin irritation, and nail deformity.
What else can Mallet Finger Injuries be?
Here are some conditions that could affect the hands and fingers:
- De Quervain tenosynovitis
- Distal interphalangeal joint dislocation
- Distal interphalangeal joint fracture/dislocation
- Distal interphalangeal volar plate avulsion fracture
- Finger amputation
- Fingertip laceration
- Jersey’s finger
- Mallet Finger Fracture
- Metacarpophalangeal ulnar ligament rupture
- Nail avulsion
- Nailbed laceration
- Ring avulsion injury
- Subungual hematoma
- Swan-neck deformity
- Trigger finger
